PurposeIntraoral stents protect the healthy tissues from ionizing radiation during external beam radiotherapy reducing mucositis, hyposalivation and osteoradionecrosis.This study investigated the radiodensity and dimensional stability of polymeric materials for suitability in construction of intraoral stents and aimed to provide clinical guidelines. MethodsSpecimens were fabricated using 4 material types namely, resin composite (ProTemp-PRO), polymethylmethacrylate (PMMA) (Enamel Temp Plus-ETP, Palapress-PAL, TAB 2000-TAB), polycaprolactone (Orfit-ORF) and silicone (Adisil-ADI, Lab Putty-LAB, Memosil2-MEM, Optosil-OPT, President Plus-PRE, Siolaplast A-SIA).They were randomly assigned to measuretheir radiodensity inHounsfield Units(HU)(12x12x11mm3) (Nradiodensity = 66; n = 6)using a computer tomograph (CBCT,Toshiba Aquillon LB scanner)at baseline and after 6 weeks. The scanning protocol was applied with and without single energy metal artifact reduction (SEMAR) scans using a slice thickness of 1 and 5 mm.The same materials have been tested for their dimensional stability (µm3)at baseline, 1, 6, 12, 24 h, 3 and 6 weeks(14 × 4 × 2 mm3)(Ndimension = 55; n = 5 per material) using stereolithography (STL) files generated by a lab scanner (L2i, Imetric4D, Courgenay, Switzerland) and analyzed using a matchingsoftware(Geomagic ControlX 2020,3D Systems).Data were analyzed using a paired t-test (alpha = 0.05). ResultsRadiodensity values (HU) were significantly affected by the material classification (p < 0.05).Polycaprolactone(43.6) presented significantly lower HU valuesfollowed by PMMA (91.3–414.9) than those of silicone materials (292.8–874.5). In terms of dimensional stability (µm3), PMMA materials (Δ:1.53–2.68) andresin composite (Δ:2.89)were significantly more dimensionally stable compared to those of silicone materials(Δ:13.64–6.63)andpolycaprolactone (Δ:-0.76) and (p < 0.05). ConclusionFor fabricating intraoral stents, when reducedradiodensity valuesarerequiredpolycaprolactone could be recommended as it fulfils the requirements for reduced radiodensity and dimensional stability. Among all silicone materials,OPT and MEMcan be recommended based on the low HU and dimensional stability.